Short Circuit Ratio (other)

	Short Circuit Ratio (other) Short circuit ratio (or SCR) has multiple meanings: * Short circuit ratio (synchronous generator), a value used to characterize the stability of an electromechanical generator * Short circuit ratio (electrical grid) In an electrical grid, the short circuit ratio (or SCR) is the ratio of: the short circuit apparent power (SCMVA) in the case of a line-line-line-ground (3LG) fault at the location in the grid where some generator is connected, to: the power rati ..., a metric to characterize the grid strength ("stiffness"). {{dab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Short Circuit Ratio (synchronous Generator) In a synchronous generator, the short circuit ratio is the ratio of field current required to produce rated armature voltage at the open circuit to the field current required to produce the rated armature current at short circuit A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit .... This ratio can also be expressed as an inverse of the saturated direct-axis synchronous reactance (in p.u.): : SCR = \frac 1 Effects of SCR values Higher SCR requires lower reactance X_S that in practice means a larger air gap. Both high and low levels of SCR have their benefits: * low SCR: in case of a short circuit, the current is proportional to SCR, therefore generators with low SCR require less protection and thus are cheaper; low SCR allows shorter air gap and lower excitation field, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]
	Short Circuit Ratio (electrical Grid) In an electrical grid, the short circuit ratio (or SCR) is the ratio of: the short circuit apparent power (SCMVA) in the case of a line-line-line-ground (3LG) fault at the location in the grid where some generator is connected, to: the power rating of the generator itself (GMW). Since the power that can be delivered by the grid varies by location, frequently a location is indicated, for example, at the point of interconnection (POI): :SCR_ = \frac SCR is used to quantify the system strength of the grid (its ability to deal with changes in active and reactive power injection and consumption). On a simplified level, a high SCR indicates that the particular generator represents a small portion of the power available at the point of its connection to the grid, and therefore the generator problems cannot affect the grid in a significant way. SCMVA is defined as a product of the voltage before the 3LG fault and the current that would flow after the fault (this worst-case combina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu]